diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/librustc_resolve/late.rs | 22 |
1 files changed, 7 insertions, 15 deletions
diff --git a/src/librustc_resolve/late.rs b/src/librustc_resolve/late.rs index f48df7faea2..666c482c680 100644 --- a/src/librustc_resolve/late.rs +++ b/src/librustc_resolve/late.rs @@ -69,6 +69,7 @@ impl PatternSource { /// Denotes whether the context for the set of already bound bindings is a `Product` /// or `Or` context. This is used in e.g., `fresh_binding` and `resolve_pattern_inner`. /// See those functions for more information. +#[derive(PartialEq)] enum PatBoundCtx { /// A product pattern context, e.g., `Variant(a, b)`. Product, @@ -1417,21 +1418,12 @@ impl<'a, 'b> LateResolutionVisitor<'a, '_> { // later passes make about or-patterns.) let ident = ident.modern_and_legacy(); - // Walk outwards the stack of products / or-patterns and - // find out if the identifier has been bound in any of these. - let mut already_bound_and = false; - let mut already_bound_or = false; - for (is_sum, set) in bindings.iter_mut().rev() { - match (is_sum, set.get(&ident).cloned()) { - // Already bound in a product pattern, e.g. `(a, a)` which is not allowed. - (PatBoundCtx::Product, Some(..)) => already_bound_and = true, - // Already bound in an or-pattern, e.g. `V1(a) | V2(a)`. - // This is *required* for consistency which is checked later. - (PatBoundCtx::Or, Some(..)) => already_bound_or = true, - // Not already bound here. - _ => {} - } - } + let mut bound_iter = bindings.iter().filter(|(_, set)| set.contains(&ident)); + // Already bound in a product pattern? e.g. `(a, a)` which is not allowed. + let already_bound_and = bound_iter.clone().any(|(ctx, _)| *ctx == PatBoundCtx::Product); + // Already bound in an or-pattern? e.g. `V1(a) | V2(a)`. + // This is *required* for consistency which is checked later. + let already_bound_or = bound_iter.any(|(ctx, _)| *ctx == PatBoundCtx::Or); if already_bound_and { // Overlap in a product pattern somewhere; report an error. |